diff --git a/providers/azureblob/src/main/java/org/jclouds/azureblob/blobstore/strategy/AzureBlobBlockUploadStrategy.java b/providers/azureblob/src/main/java/org/jclouds/azureblob/blobstore/strategy/AzureBlobBlockUploadStrategy.java
index d7258754a2..44755551fb 100644
--- a/providers/azureblob/src/main/java/org/jclouds/azureblob/blobstore/strategy/AzureBlobBlockUploadStrategy.java
+++ b/providers/azureblob/src/main/java/org/jclouds/azureblob/blobstore/strategy/AzureBlobBlockUploadStrategy.java
@@ -35,6 +35,7 @@ import java.util.List;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
 
 /**
  * Decomposes a blob into blocks for upload and assembly through PutBlock and PutBlockList
@@ -57,7 +58,7 @@ public class AzureBlobBlockUploadStrategy implements MultipartUploadStrategy {
    public String execute(String container, Blob blob) {
       String blobName = blob.getMetadata().getName();
       Payload payload = blob.getPayload();
-      long length = payload.getContentMetadata().getContentLength();
+      Long length = payload.getContentMetadata().getContentLength();
       checkNotNull(length,
             "please invoke payload.getContentMetadata().setContentLength(length) prior to azure block upload");
       checkArgument(length <= (MAX_NUMBER_OF_BLOCKS * MAX_BLOCK_SIZE));
@@ -81,7 +82,7 @@ public class AzureBlobBlockUploadStrategy implements MultipartUploadStrategy {
          blockIds.add(blockId);
          client.putBlock(container, blobName, blockId, block);
       }
-      assert bytesWritten == length;
+      checkState(bytesWritten == length, "Wrote " + bytesWritten + " bytes, but we wanted to write " + length + " bytes");
       return client.putBlockList(container, blobName, blockIds);
    }
 }
diff --git a/providers/azureblob/src/main/java/org/jclouds/azureblob/domain/internal/BlobBlockPropertiesImpl.java b/providers/azureblob/src/main/java/org/jclouds/azureblob/domain/internal/BlobBlockPropertiesImpl.java
index 7e412f9ff5..b2d15d7933 100755
--- a/providers/azureblob/src/main/java/org/jclouds/azureblob/domain/internal/BlobBlockPropertiesImpl.java
+++ b/providers/azureblob/src/main/java/org/jclouds/azureblob/domain/internal/BlobBlockPropertiesImpl.java
@@ -19,6 +19,7 @@ package org.jclouds.azureblob.domain.internal;
 import org.jclouds.azureblob.domain.BlobBlockProperties;
 
 import com.google.common.base.Objects;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Representation of the blocks which compose a Blob
@@ -29,7 +30,7 @@ public class BlobBlockPropertiesImpl implements BlobBlockProperties {
    private final boolean committed;
 
    public BlobBlockPropertiesImpl(String blockName, long contentLength, boolean committed) {
-      this.blockName = blockName;
+      this.blockName = checkNotNull(blockName);
       this.contentLength = contentLength;
       this.committed = committed;
    }
diff --git a/providers/azureblob/src/main/java/org/jclouds/azureblob/predicates/validators/BlockIdValidator.java b/providers/azureblob/src/main/java/org/jclouds/azureblob/predicates/validators/BlockIdValidator.java
index 9003f87c74..cd6d53f771 100644
--- a/providers/azureblob/src/main/java/org/jclouds/azureblob/predicates/validators/BlockIdValidator.java
+++ b/providers/azureblob/src/main/java/org/jclouds/azureblob/predicates/validators/BlockIdValidator.java
@@ -33,8 +33,8 @@ import org.jclouds.predicates.Validator;
 @Singleton
 public class BlockIdValidator extends Validator<String> {
    @Override
-   public void validate(@Nullable String s) throws IllegalArgumentException {
-      if (s.length() > 64)
+   public void validate(String s) throws IllegalArgumentException {
+      if (s == null || s.length() > 64)
          throw new IllegalArgumentException("block id:" + s + "; Block Ids must be less than or equal to 64 bytes in size");
 
    }
diff --git a/providers/azureblob/src/main/java/org/jclouds/azureblob/xml/BlobBlocksResultsHandler.java b/providers/azureblob/src/main/java/org/jclouds/azureblob/xml/BlobBlocksResultsHandler.java
index 4a9506508b..6a566e72f4 100755
--- a/providers/azureblob/src/main/java/org/jclouds/azureblob/xml/BlobBlocksResultsHandler.java
+++ b/providers/azureblob/src/main/java/org/jclouds/azureblob/xml/BlobBlocksResultsHandler.java
@@ -30,6 +30,7 @@ import com.google.common.collect.Lists;
 
 /**
  * Parses the following document:
+ * <pre>
  * <?xml version="1.0" encoding="utf-8"?>
  * <BlockList>
  * <CommittedBlocks>
@@ -39,6 +40,7 @@ import com.google.common.collect.Lists;
  * </Block>
  * <CommittedBlocks>
  * </BlockList>
+ * </pre>
  */
 public class BlobBlocksResultsHandler extends ParseSax.HandlerWithResult<ListBlobBlocksResponse> {